Res. Chem. Intermed.
, Vol. 30, No. 9, pp. 847–856 (2004)
Also available online - www.vsppub.com
Laser-induced changes in silver metal nanoparticles
incorporated in viscous media
MEDHA RELE, SUDHIR KAPOOR
, DIPAK K. PALIT
and TULSI MUKHERJEE
Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre,
Mumbai 400 085, India
Received 4 June 2004; accepted 6 July 2004
Abstract—The effect of laser pulse irradiation on silver metal nanoparticles in ethylene glycol
and glycerol is studied and compared with the parallel processes in aqueous solutions. The
inﬂuence of 355 nm laser pulse irradiation at the surface plasmon frequency and on the size of the
silver nanoparticles is examined by UV-Vis absorption spectroscopy and by transmission electron
microscopy. It appears that viscosity of the medium plays a crucial role for the stabilization of the
melted particles in the absence of the stabilizer. In ethylene glycol containing PVP, fragmentation
of particles was observed. In neat glycerol, similar excitation led to morphological changes as the
nanoparticles fused to produce particles of larger size. The changes in reduction of shape and size are
considered to occur through melting and vaporization of the silver nanoparticles.
Keywords: Nanoparticles; electron microscopy; laser irradiation.
Synthesis of nanoparticles is an interesting area of research in solid state chemistry.
The preparation of nanometer-sized and monodisperse particles is one of the most
important challenges and is an endless endeavour [1–16]. Therefore, new methods
for the preparation of nanoparticles are frequently reported in the literature.
Numerous studies have been reported on the dependence of electron–electron
and electron–phonon processes on the particle size [17– 21]. Also, a few reports
exist on the energy dissipation between metallic nanoparticles and its environ-
ment [8, 9, 13, 14], Bigot et al. [22, 23] have studied the electron dynamics in a
glass matrix and compared the results obtained in thin ﬁlms. Recently, El-Sayed
To whom correspondence should be addressed. Tel.: (91-22) 2559-0298. Fax: (91-22) 2550-5151.